Encryption can be a relatively simple process, or as difficult as the user wants to make it. The degree of difficulty does not necessarily relate to the security of the encryption method. Often there has been a need to protect information from ‘prying eyes’. Traditionally, several methods can be used to encrypt data streams, all of which can easily be implemented through software, but not so easily decrypted when either the original or its encrypted data stream are unavailable. (When both source and encrypted data are available, code-breaking becomes much simpler, though it is not necessarily easy). The best encryption methods have little effect on system performance, and may contain other benefits such as data compression built in the system.